Hmm. My attempt at answering this: The "incidental decisions" is about such actions as choosing male candidates over female candidates with identical qualifications, ignoring women`s contributions at meetings and then agreeing strongly when a man later says the exact same thing, and so on. As for "excluding the threat", maybe it refers to perceptions of women as being less skilled, rather than having the cognitive dissonance involved in admitting you're picking the man because he is male.